UBUNTU-CVE-2026-53331: Medium severity ubuntu/linux-hwe-edge vulnerability
In the Linux kernel, the following vulnerability has been resolved: slimbus: qcom-ngd-ctrl: Avoid ABBA on txlock/ctrl->lock During the SSR/PDR down notification the txlock is taken with the intent to provide synchronization with active DMA transfers. But during this period qcomslimngddown() is invoked, which ends up in slimreportabsent(), which takes the slimcontroller lock. In multiple other codepaths these two locks are taken in the opposite order (i.e. slimcontroller then txlock). The result is a lockdep splat, and a possible deadlock: rprocctl/449 is trying to acquire lock: ffff00009793e620 (&ctrl->lock){+.+.}-{4:4}, at: slimreportabsent (drivers/slimbus/core.c:322) slimbus but task is already holding lock: ffff00009793fb50 (&ctrl->txlock){+.+.}-{4:4}, at: qcomslimngdssrpdrnotify (drivers/slimbus/qcom-ngd-ctrl.c:1475) slimqcomngdctrl which lock already depends on the new lock. Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&ctrl->txlock); lock(&ctrl->lock); lock(&ctrl->txlock); lock(&ctrl->lock); The assumption is that the comment refers to the desire to not call qcomslimngdexitdma() while we have an ongoing DMA TX transaction. But any such transaction is initiated and completed within a single qcomslimngdxfermsg(). Prior to calling qcomslimngdexitdma() the slimcontroller is torn down, all child devices are notified that the slimbus is gone and the child devices are removed. Stop taking the txlock in qcomslimngdssrpdrnotify() to avoid the deadlock.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
ubuntu/linux-aws-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1117.124~20.04.1 - Upgrade
Upgrade
ubuntu/linux-azure-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1123.132~20.04.1 - Upgrade
Upgrade
ubuntu/linux-azure-fde-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1122.131~20.04.1 - Upgrade
Upgrade
ubuntu/linux-gcp-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1118.128~20.04.1 - Upgrade
Upgrade
ubuntu/linux-hwe-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-198.208~20.04.1 - Upgrade
Upgrade
ubuntu/linux-ibm-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1111.115~20.04.1 - Upgrade
Upgrade
ubuntu/linux-intel-iotg-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1112.118~20.04.1 - Upgrade
Upgrade
ubuntu/linux-lowlatency-hwe-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-195.205~20.04.1 - Upgrade
Upgrade
ubuntu/linux-oracle-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1114.120~20.04.1 - Upgrade
Upgrade
ubuntu/linux-riscv-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1111.115~20.04.1 - Upgrade
Upgrade
ubuntu/linuxto a version that resolves this vulnerability.Fixed in 5.15.0-198.208 - Upgrade
Upgrade
ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 5.15.0-1117.124 - Upgrade
Upgrade
ubuntu/linux-aws-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-1066.69~22.04.1 - Upgrade
Upgrade
ubuntu/linux-azureto a version that resolves this vulnerability.Fixed in 5.15.0-1123.132 - Upgrade
Upgrade
ubuntu/linux-azure-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-1070.78~22.04.1 - Upgrade
Upgrade
ubuntu/linux-azure-fdeto a version that resolves this vulnerability.Fixed in 5.15.0-1122.131 - Upgrade
Upgrade
ubuntu/linux-azure-fde-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-1068.75~22.04.1 - Upgrade
Upgrade
ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 5.15.0-1118.128 - Upgrade
Upgrade
ubuntu/linux-gcp-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-1070.78~22.04.1 - Upgrade
Upgrade
ubuntu/linux-gketo a version that resolves this vulnerability.Fixed in 5.15.0-1113.119 - Upgrade
Upgrade
ubuntu/linux-gkeopto a version that resolves this vulnerability.Fixed in 5.15.0-1100.108 - Upgrade
Upgrade
ubuntu/linux-ibmto a version that resolves this vulnerability.Fixed in 5.15.0-1111.115 - Upgrade
Upgrade
ubuntu/linux-ibm-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-1066.67~22.04.1 - Upgrade
Upgrade
ubuntu/linux-intel-iotgto a version that resolves this vulnerability.Fixed in 5.15.0-1112.118 - Upgrade
Upgrade
ubuntu/linux-kvmto a version that resolves this vulnerability.Fixed in 5.15.0-1109.114 - Upgrade
Upgrade
ubuntu/linux-lowlatencyto a version that resolves this vulnerability.Fixed in 5.15.0-195.205 - Upgrade
Upgrade
ubuntu/linux-lowlatency-hwe-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-146.146.1~22.04.1 - Upgrade
Upgrade
ubuntu/linux-nvidiato a version that resolves this vulnerability.Fixed in 5.15.0-1112.113 - Upgrade
Upgrade
ubuntu/linux-nvidia-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-1064.67~22.04.1 - Upgrade
Upgrade
ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 5.15.0-1114.120 - Upgrade
Upgrade
ubuntu/linux-riscv-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-146.146~22.04.1 - Upgrade
Upgrade
ubuntu/linux-xilinx-zynqmpto a version that resolves this vulnerability.Fixed in 5.15.0-1080.84 - Upgrade
Upgrade
ubuntu/linux-bluefieldto a version that resolves this vulnerability.Fixed in 5.15.0-1101.103 - Upgrade
Upgrade
ubuntu/linux-intel-iot-realtimeto a version that resolves this vulnerability.Fixed in 5.15.0-1109.111 - Upgrade
Upgrade
ubuntu/linux-realtimeto a version that resolves this vulnerability.Fixed in 5.15.0-1116.125 - Upgrade
Upgrade
ubuntu/linux-realtime-6.8to a version that resolves this vulnerability.Fixed in 6.8.1-1061.62~22.04.1 - Upgrade
Upgrade
ubuntu/linux-aws-fipsto a version that resolves this vulnerability.Fixed in 5.15.0-1117.124+fips1 - Upgrade
Upgrade
ubuntu/linux-azure-fipsto a version that resolves this vulnerability.Fixed in 5.15.0-1123.132+fips1 - Upgrade
Upgrade
ubuntu/linux-fipsto a version that resolves this vulnerability.Fixed in 5.15.0-198.208+fips1 - Upgrade
Upgrade
ubuntu/linux-gcp-fipsto a version that resolves this vulnerability.Fixed in 5.15.0-1118.128+fips1 - Upgrade
Upgrade
ubuntu/linuxto a version that resolves this vulnerability.Fixed in 6.8.0-146.146 - Upgrade
Upgrade
ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 6.8.0-1066.69 - Upgrade
Upgrade
ubuntu/linux-aws-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1012.12~24.04.1 - Upgrade
Upgrade
ubuntu/linux-azureto a version that resolves this vulnerability.Fixed in 6.8.0-1070.78 - Upgrade
Upgrade
ubuntu/linux-azure-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1014.14~24.04.1 - Upgrade
Upgrade
ubuntu/linux-azure-fdeto a version that resolves this vulnerability.Fixed in 6.8.0-1068.75 - Upgrade
Upgrade
ubuntu/linux-azure-fde-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1013.13~24.04.1 - Upgrade
Upgrade
ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 6.8.0-1070.78 - Upgrade
Upgrade
ubuntu/linux-gcp-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1011.11~24.04.1 - Upgrade
Upgrade
ubuntu/linux-gketo a version that resolves this vulnerability.Fixed in 6.8.0-1065.73 - Upgrade
Upgrade
ubuntu/linux-gkeopto a version that resolves this vulnerability.Fixed in 6.8.0-1051.55 - Upgrade
Upgrade
ubuntu/linux-hwe-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-31.31~24.04.1 - Upgrade
Upgrade
ubuntu/linux-ibmto a version that resolves this vulnerability.Fixed in 6.8.0-1066.67 - Upgrade
Upgrade
ubuntu/linux-lowlatencyto a version that resolves this vulnerability.Fixed in 6.8.0-146.146.1 - Upgrade
Upgrade
ubuntu/linux-nvidiato a version that resolves this vulnerability.Fixed in 6.8.0-1064.67 - Upgrade
Upgrade
ubuntu/linux-nvidia-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1018.18~24.04.1 - Upgrade
Upgrade
ubuntu/linux-nvidia-lowlatencyto a version that resolves this vulnerability.Fixed in 6.8.0-1064.67.1 - Upgrade
Upgrade
ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 6.8.0-1063.66 - Upgrade
Upgrade
ubuntu/linux-oracle-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1011.11~24.04.1 - Upgrade
Upgrade
ubuntu/linux-riscv-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-31.31.1~24.04.1 - Upgrade
Upgrade
ubuntu/linux-bluefieldto a version that resolves this vulnerability.Fixed in 6.8.0-1032.37 - Upgrade
Upgrade
ubuntu/linux-realtimeto a version that resolves this vulnerability.Fixed in 6.8.1-1061.62 - Upgrade
Upgrade
ubuntu/linux-aws-fipsto a version that resolves this vulnerability.Fixed in 6.8.0-1066.69+fips1 - Upgrade
Upgrade
ubuntu/linux-azure-fipsto a version that resolves this vulnerability.Fixed in 6.8.0-1069.77+fips1 - Upgrade
Upgrade
ubuntu/linux-fipsto a version that resolves this vulnerability.Fixed in 6.8.0-146.146+fips1 - Upgrade
Upgrade
ubuntu/linux-gcp-fipsto a version that resolves this vulnerability.Fixed in 6.8.0-1070.78+fips1 - Upgrade
Upgrade
ubuntu/linuxto a version that resolves this vulnerability.Fixed in 7.0.0-31.31 - Upgrade
Upgrade
ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 7.0.0-1012.12 - Upgrade
Upgrade
ubuntu/linux-azureto a version that resolves this vulnerability.Fixed in 7.0.0-1014.14 - Upgrade
Upgrade
ubuntu/linux-azure-fdeto a version that resolves this vulnerability.Fixed in 7.0.0-1013.13 - Upgrade
Upgrade
ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 7.0.0-1011.11 - Upgrade
Upgrade
ubuntu/linux-gketo a version that resolves this vulnerability.Fixed in 7.0.0-1006.7 - Upgrade
Upgrade
ubuntu/linux-ibmto a version that resolves this vulnerability.Fixed in 7.0.0-1013.13 - Upgrade
Upgrade
ubuntu/linux-nvidiato a version that resolves this vulnerability.Fixed in 7.0.0-1018.18 - Upgrade
Upgrade
ubuntu/linux-nvidia-bosto a version that resolves this vulnerability.Fixed in 7.0.0-2018.18 - Upgrade
Upgrade
ubuntu/linux-oem-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1013.13 - Upgrade
Upgrade
ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 7.0.0-1011.11 - Upgrade
Upgrade
ubuntu/linux-raspito a version that resolves this vulnerability.Fixed in 7.0.0-1019.19 - Upgrade
Upgrade
ubuntu/linux-realtimeto a version that resolves this vulnerability.Fixed in 7.0.0-31.31.1 - Upgrade
Upgrade
ubuntu/linux-riscvto a version that resolves this vulnerability.Fixed in 7.0.0-31.31.1 - Compensating control
Stop taking tx_lock in qcom_slim_ngd_ssr_pdr_notify() to avoid the ABBA deadlock with the slim_controller lock.
Event History
Frequently Asked Questions
Which Ubuntu kernel packages are listed as affected?
The listed software includes ubuntu/linux, ubuntu/linux-aws, ubuntu/linux-azure, ubuntu/linux-azure-fde, ubuntu/linux-gcp, ubuntu/linux-gke, ubuntu/linux-realtime, and ubuntu/linux-riscv.
What conditions are required to trigger the issue?
The issue involves concurrent lock acquisition during an SSR/PDR down notification and active or synchronized DMA transmission handling in the Qualcomm SLIMbus NGD controller. Exploitation requires local access and low privileges; no user interaction is required.
What is the likely impact if the locking issue is triggered?
The conflicting tx_lock and slim_controller lock acquisition order can cause a deadlock. The reported security impact is availability only, with high availability impact and no confidentiality or integrity impact.